Abstract: A process for monitoring a direction of drive from an automatic or automated vehicle transmission at near-zero vehicle speed via an engaged gear. A desired direction of drive of the transmission is determined from an engaged gear at the time the vehicle begins motion. An actual direction of drive is determined from the transmission and if different from the desired direction of driver an error signal is produced. The process including determining the actual drive either from a sensed rotational direction of a transmission input shaft and a sensed rotational direction of a transmission output shaft or a sensed valve setting, a sensed pressure in an transmission electro-hydraulic control system or on a transmission shifting element or from a sensed direction of rotation of a transmission gearset element or from axial movement or force of a transmission constructional element.

Abstract: A vehicular parallel hybrid drivetrain contains a combustion engine, electric motor and drive output and a method of operating the drivetrain. A respective shift element device (6, 7) with continuously variable transmission capacity is provided, between the combustion engine and the electric motor and between the electric motor and the drive. The shift element device (6), between the combustion engine and electric motor, comprises a speed-dependent hydraulic coupling element and a frictional shift element in a parallel power branch. The shift element device (6) has continuously adjustable transmission capacity and is bridged, via the hydraulic coupling element. The hydraulic coupling element actively couples with the electric motor, via a free-wheel overrunning connection (8). This coupling disengages when the speed of the coupling element side of the coupling element is lower than the speed of the electric motor in the area of the free-wheel overrunning connection.

Abstract: An apparatus for compensating the viscous characteristics of a hydraulic medium in a pressure line (10) in which apparatus a pressure nozzle (12) with constant geometry and constant through-flow cross-section is located in the pressure line (10). It is provided according to the invention that in the pressure Line (10) upstream or downstream of the pressure nozzle (12) at least one channel-shaped area (11, 28) is made or situated which, compared to the pressure nozzle (12), has a smaller through-flow cross-section and a larger axial extension and that the control pressure (P_SekV) abutting between the channel-shaped area (11, 28) and the pressure nozzle (12) can be supplied via a control pressure line (13) to a shift valve (14).

Abstract: An apparatus for operating a hydrodynamic torque converter and a corresponding converter-bypass clutch of a transmission, having a solenoid valve communicating with a variable pressure control valve. The respective valve stem assembly thereof having surfaces which react to an application of hydraulic pressure. Each valve being controlled by a pilot pressure countering a spring arrangement. A spent fluid flow side of the torque converter communicates with a spent fluid flow aperture of the solenoid valve. The valve stem assembly related, to the solenoid valve is blocked by a supply aperture of the solenoid valve and is in operational connection with an auxiliary pressure control valve. A supply aperture of the variable pressure controller valve is connected with an operational pressure aperture of the pressure control valve, which, can be connected with a piston space of the converter-bypass clutch, which pressurized hydraulic fluid can be applied.

Abstract: An apparatus operating a hydrodynamic torque converter and a corresponding converter-bypass clutch of a transmission. The apparatus having a line system, a solenoid valve and a therewith coacting variable pressure controlling valve. A valve stem assembly respectively of the solenoid valve and the pressure control valve are controllable by subjection to a pilot pressure counter to a spring arrangement. A spent flow of the torque converter is, by way of a piston chamber of the converter-bypass clutch, which chamber is subjected to hydraulic fluid pressure of the spent flow of the torque converter, by means of an operational pressure aperture valve and a relief control aperture valve of the pressure control valve, connectable to a spent flow control aperture valve of the solenoid valve. By way of the piston chamber, this spent flow communicates with the hydraulic system through the spent flow control aperture valve of the solenoid valve.

Abstract: A device for operating a starter mechanism actively connected with a hydraulic supply circuit of a transmission unit. The starter mechanism has a piston chamber subject to hydraulic pressure for activating a frictional shift element and a hydraulic chamber subject to hydraulic pressure for the cooling and lubricating an area of the starter mechanism. A hydraulic pressure between a lubrication pressure control port of a second pressure relief valve and the hydraulic chamber and equivalent to a lubrication pressure, is exerted on a second back pressure outlet port of a first relief valve, which acts on a valve slide of the first relief valve in the opposite direction relative to the working pressure exerted on a first back pressure outlet port of the first relief valve so that the pressure feed-back of the hydraulic pressure to the first relief valve occurs additively to the pilot signal characteristic of the first relief valve.

Abstract: A hydraulic system of a transmission, for an automatic transmission of a motor vehicle, having several pressure circuits which can be loaded with hydraulic fluid from a pressure source and in relation to the supply of different areas of the transmission are differently prioritized. The pressure in the pressure circuits is adjustable according to a system valve and one of the pressure circuits comprises a cooling device for the hydraulic fluid and a lubrication circuit located downstream of the cooling device. Between the cooling device and the lubrication circuit is provided a bypass pipe, blockable via a valve unit, which can be controlled via the valve unit so that the hydraulic fluid flow rate to be passed via the cooling device can be adjusted without changing the hydraulic fluid flow rate to be fed to the lubrication circuit.

Abstract: A method for operating power train side components of a motor vehicle. Using a control device of a motor, at least one motor parameter is issued and delivered via a databus to at least one control device of one other power drive side component working independently of the motor control device in order to operate all or each one of the power drive side components dependent in a first inventive aspect, a behavior of the respective other power drive side components that adjusts itself according to the motor torque actually made available by the motor is evaluated. In second inventive aspect, the motor torque issued by the motor control device is compared with a torque stored according to motor operation parameters in the control device working independently of the motor control device.

Abstract: A device for controlling a hydraulically operable switching element (2) of an automatic transmission of a vehicle with a position valve mechanism (3) having a main switch piston (6) which is spring biased into a first switch position and a second switch position with a pilot pressure (P_MV) which is adjustable through an electrically operated actuator (5). An additional switch piston (7) and the main switch piston (6) are axially actuated in a valve housing (8). Depending on the position of the pistons (6, 7), faces (6A, 7A) of the respective pistons are either spaced apart or adjacent. The additional switch piston (7) is adjustable depending on a pilot pressure (p_K) of a switching element which engages a gear for forward drive.

Abstract: A control valve (12) comprising a valve housing (13) having two inflow openings (6, 7) and one outflow opening (8), in whose inner valve chamber (14), which is filled with a pressurized medium, a switching mechanism (20, 32) is displaceably arranged between two switching positions, while the switching mechanism (20, 32) respectively opens one of the inflow openings of the valve housing (13) and respectively closes the other inflow opening in both switching positions. In order to shorten the switching time in a control valve of this kind, it is provided that the switching mechanism (20, 32) comprises at least two separate sealing mechanisms (17, 18; 24, 25), which are movably arranged along respectively allocated circular arc sections approximately coaxially to the inflow openings (6, 7) in order to open and close the two openings (6, 7).

Abstract: A hydraulic system (1) for a transmission with a starter clutch is described. The hydraulic system (1) is designed to comprise a primary circuit (24) and a secondary circuit (5). A cooling system (9) for the starter clutch, a radiator (7) for hydraulic fluid and a lubricant supply (10) for the transmission are integrated into the secondary circuit (5), where the radiator (7) is arranged upstream from the cooling system (9) for the starter clutch. A volume flow of the hydraulic fluid through the radiator (7) can be limited by way of a controllable bypass line (11), which opens up into the secondary circuit (5) downstream from the radiator (7) and upstream from the cooling system (9) for the starter clutch.

Abstract: A braking method for a vehicle is proposed as a safety measure and replacement function if the brake system fails, in particular the X-by-wire brake system of a motor vehicle, in which the vehicle is braked with the help of the transmission by a defined engagement of frictional shift elements until the vehicle comes to rest, such that the combination of frictional shift elements actuated when the vehicle's working brake system fails does not correspond to the shift logic of a gear during normal driving operation of the vehicle.

Abstract: A device for the control of a hydraulically actuated clutch (1) of an automatic transmission of a motor vehicle having a slide-valve mechanism (3) is proposed, in which a valve piston (4) can move between a first working space (7) which can be pressurized via a control line (8) with a control pressure (p_MV) adjustable by means of an electrically operated actuator (9) and a restoring space (10) containing a restoring spring (11) that acts on the valve piston (4). The valve piston (4) is made with several piston sections (4A, 4B) that delimit a pressure space (12) which is connected via a line (13) to a clutch space (2) of the clutch (1) and which, depending on the position of the valve piston (4), has a connection to a pressure supply line (14) delivering a system pressure (p_sys) or to a pressure-relief line (15).

Abstract: A hydraulic system of a transmission, especially of an automatic transmission of a motor vehicle, having several pressure circuits which can be loaded with hydraulic fluid from a pressure source and in relation to the supply of different areas of the transmission are differently prioritized. The pressure in the pressure circuits is adjustable according to a system valve and one of the pressure circuits comprises a cooling device for the hydraulic fluid and a lubrication circuit located downstream of the cooling device. Between the cooling device and the lubrication circuit is provided a bypass pipe lockable via a valve unit which can be controlled via the valve unit so that the hydraulic fluid flow rate to be passed via the cooling device can be adjusted without changing the hydraulic fluid flow rate to be fed to the lubrication circuit.

Abstract: A shift element sub-assembly for a transmission having two axially adjacent shift elements (2, 3) that are located in a transmission housing (1). The discs of both shift elements (2, 3) lie axially adjacent in the interior of the disc carrier (4) and are separated from one another by a central partition (40) of the disc carrier (4). Each shift element (2, 3) has a piston (23, 33) and a closing pressure chamber (24, 34), and at least one resetting element (27, 37, 39) for resetting the piston. Additionally, each shift element (2, 3) has a secondary piston (26, 36), which acts on the discs of each shift element (2, 3) in opposition to a resetting force of the resetting element (27, 37, 39) of each shift element (2, 3), via the piston (23, 33) of each shift element (2, 3), and at least one resetting element (27, 37, 39) of the shift element sub-assembly is configured as a drain pressure chamber (27, 37) that can be hydraulically or pneumatically actuated.

Abstract: A device to allow for emergency operation of an automatic-transmission motor vehicle, having a monitoring device to monitor pre-determined operating parameters, a diagnostic device to detect faults, a control device to activate an alternative function, and an output device by means of which the fault may be presented to the driver. The control device provides the driver an emergency operation capability while providing an alternative function depending on the degree of the fault.

Abstract: A proportional pressure control valve is described, which comprises a valve part (1) with outlet and inlet openings (4) and at least one closing element (2) for the control of an orifice (5). The hydraulically effective cross-section of the valve part (1) is determined by the size and shape of the inlet opening (4). The axial longitudinal axis of the inlet opening (4) is perpendicular to the longitudinal axis of the closing element (2). The resultant force action on the closing element (2) has an advantageous effect on the quality of the valve function especially at low temperatures.

Abstract: A device for control of a hydraulically actuatable shifting element of a motor vehicle transmission, having one clutch piston which defines, with a first surface, a hydraulically pressurizable piston space and, with a second surface of different size, a hydraulically pressurizable reset space and comprising a first clutch valve associated with the piston space, a second clutch valve associated with the reset space and a holding valve associated with the reset space. The valves can be moved according to a control pressure adjusted by a pressure adjuster, a change between a pressurization of the clutch piston on the piston space side and on the reset space, side being performed as a control function so that the clutch piston on its surface facing the reset space is pressurized in an unshifted state of the shifting element and is discharged in a shifted state of the shifting element.

Abstract: The invention relates to a parking brake system for transmissions of motor vehicle, especially for an automatic transmission and an automated selector transmission, having one parking brake for blocking or releasing the transmission according to actuation signals of a control device, especially by a pawl engaging and disengaging in a parking brake gear connected with the output of the transmission, an electric operative connection between the control device in the interior of the motor vehicle and the parking brake, a spring accumulator (9) for actuating the parking brake and a pressure-controlled release device of the parking brake. It is proposed to load the release device (10) when releasing the parking brake with a negative pressure independent of the transmission and which is preferably taken from the suction system (15) of the internal combustion engine of the motor vehicle or from a negative pressure brake force booster of the motor vehicle.

Abstract: An apparatus for compensating the viscous characteristics of a hydraulic medium in a pressure line (10) in which apparatus a pressure nozzle (12) with constant geometry and constant through-flow cross-section is located in the pressure line (10). It is provided according to the invention that in the pressure Line (10) upstream or downstream of the pressure nozzle (12) at least one channel-shaped area (11, 28) is made or situated which, compared to the pressure nozzle (12), has a smaller through-flow cross-section and a larger axial extension and that the control pressure (P_SekV) abutting between the channel-shaped area (11, 28) and the pressure nozzle (12) can be supplied via a control pressure line (13) to a shift valve (14).